Automatic door check with tension contrivance and mechanical brake



vJuly25,-1939. v 7 w. SCHMIDT) 2,161,409"

AUTOIATIC DOOR CHECK WITH TENSION CONTBIVANCE A ND IECHANIOAL BRAKE Filed June 9, 1938 Patented July 25,1939 I I E 'NPATENT OFFICE AUTOMATIC DOOR CHECK WITH TENSION CONTRIVANCE AND MECHANICAL BRAKE Walter Schmidt, Menden, Iserlohn, Germany Application June 9, 1938, Serial No. 212,786

In Germany July 10, 1937 8 claims. (on. 16-49) Door checks with tension contrivance and ing for the passage of the adjusting screw 6. mechanical brake are known, also those in which The cover 3 has an opening l-for the passage of the mechanical braking device can be used for the tension wheel 8 for the closing spring 9. The

'' different turning directions. Furthermore it has spring 9 is held with one end in a slot I0 of the already been proposed to use a brake drum for cover 3; the other end of the spring. 9 engages the mechanical braking device. i into a suitable fixing contrivance (e. g, a groove) Compared with this known state of the art ofthe tension wheel 8. The spring 9 can, of the present invention consists in the braking part course, be fixed to some other part of the casing being permanently and uniformly engaged with. I, e. g., in a prolongation Illa of the slot Ill'shown the braked parts, so that the end play is avoided in the casing, the only object being to hold the .lo and the braking effect is always the same. Furspring at one end firmly to a fixed part of the thermore in thisinvention an adjusting contrivcontrivance. ance acts on a cone, the friction'or braking effect Theaxle l2, which is free to move independentof which can be adjusted to various degrees. Ac- 1y of the tension wheel, extends through the tencording to another construction of this invention sion wheel. 8 and is provided with the square 1 the braking efiect is obtained with the help of end l3. On the square end I3 is mounted, in a 'brake drum, the braking of which is effected, the usualmanner, one end ll of the arm of the according to the turning direction, bythe use of door check which, by means of a pawl l5, entiltable fixing contrivances in the form of U- gagesa toothed end on the wheel 8 so that move-' shaped, grippers. ment of the arm is upon opening of the door By these features of the'invention, as already causes winding and tensioning of the spring 9. mentioned, the end play is avoided; thus the door Hinged to the other end of the arm i4 is another closes a certain distance before the brake enters lever arm with a contrivance at its opposite end into play. That is because, contrary to the com for fixing it to the door or the wall, adjustable trivances hitherto known, no play is left betweenby spindles in the usual way (not shown in the the brake and, the part to be braked, -so that draining). the brake engages immediately and has not, as The axle. l2 carries a threaded extension IS in the case of the known contrivances, first to to enable a compression spring H to be held by overcome this play, which gives rise to the soa threaded sleeve l8 with adjusting flange l9 called end play. that can be screwed on to the threaded, extension In that form of construction described in the I6. The threaded sleeve I 8 has a bore passing following, this effect is obtained .by the inclined right through it with inside thread, in. which the position of grippers, which is always present, adjusting screws is screwed. It will be noted that whereby the grippers are always engaged with in assembling the device, member I8 is passed the casing; also the braking cone is always enthrough the opening 5 from above downwardly gagedwith the casing, so that braking always in Fig. 1. The shaft i2 is then connected with commences immediately; moreover by the conithe member l8 and the screw 6 is screwed into cal shapeof the brake the wear and tear is re, the outer endof said member is, thereby assemduced to a minimum. bling the parts. I l

On the drawing the subject of this invention is The spring I! presses against a disc 20, which 40 shown in one construction as an example, in revolves on the shaft l2. This disc presses in which: I g turn against the cone 2|, which is held on two Fig. 1 is the complete device in longitudinal catches 23 by means of two grooves 22, the catches cross section, .being firmly connected 'to the shaft, I2. The

Fig. 2 is a side elevation with certain of. the cone 2| can therefore be displaced in the lonparts shown in dotted lines within the device. gitudinal direction of the shaft, but does not Fig. 3 is a section on the line 3-4 of Figure 1. revolve about it, and is subjected to the pres- Fig. 4 is a detail view showing certain of the sure of the spring ll. The cone is gripped by a parts of the "invention removed from the casing" brake drum 24 that can revolve as'desired round and with certain of the removed parts beingbrothe shaft I2, being secured 'by a fixing ring 25 so keen away'to show in section. or bysome other means against displacement Fig. 1 shows the maincasing part 'l-with the on the shaft l2 beyond a certain point, namely fixing plate 2, the removable cover 3 which can against the pressure from above exercised by the be fastened down to the casing I with the help braking cone 2| through the spring I1. ofthebolt-holes I. The casing I has an open- The brake drum 24 is guided by four U-shaped stirrups distributed over its circumference, these -U-shaped stirrups 26 being held with lone arm in the bearings 21. These bearings 21;a-re in firm connection with the casing I and may j-have any shape, but must be so formed as to allow the stirrups 26 a certain amount of play in the bearingsto enable them to tilt slightly sideways. With their other arm the U-shaped stirrups 26 are led through a ring provided with springs in such a manner that each stirrup 26 is held in a tilted position between two springs 29 on this ring. By virtue of this tilted position the stirrup 26 will normally hold fast the brake drum 24 (see Fig."

4). Here it can be seen how the stirrup 26 is tilted to the right, i. e., in the direction opposite to theturn for the door opening, by the space 33 which is shaded.

The braking effect is suspended only when the stirrups 26 are brought into a vertical position (not tilted) or when the tilt is relieved by the brake drum turning in the direction corresponding to the direction when opening the door. When closing the door. the drum 24, carried by the cone 2I firmly seated on the axle I2,

remains rigid and is held fast as a consequence of the stirrups 26 being again given a tilt owing to the friction of the stirrups 26 against the drum 24, so that they now hold the drum 24 fast, and then the friction of the cone 2I within the drum 24 takes up the brak ng effect against the spring closing effect.

The contrivance works as follows:

When the door is opened the spring 9 is stretched bythe lever arm I4 with the help I5, as is usual with door checks of this kind, till the door has been opened to the desired extent. The elastic ring 28 is held down to the casing I by an adjusting screw 30, which passes through a slot 3| of the casing and a cover plate 32. The adjusting screw 30 can be displaced on the casing to a certain extent rightor left according to the size of the slot 3i and the tension of the ring 28, to enable the stirrups 26 to be tilted to the right or left in the position of rest, so that the door check may be used both for doors opening-to the right and those opening to the left.

-When the door is Opened all those parts turn which are directly or indirectly connected to the axle I2, e. g., the cone 2I, the brake drum 24, the axle extension 6, I8, I9, the tension wheel.

of rotation of the shaft I2 when the door is opened, i. e., with this direction of rotation the brake drum 24 tries tobring the stirrups 26 into a vertical position, into that position in which no braking effect occurs because the length of the edge does not permit it. Each stirrup is able to y eld somewhat, because in the elastic ring 28 the grooves which guide the stirrup exceed to a considerable extent the width of the head of the stirrup, this extra space being filled in with springs which permit the stirrup head to yield slightly up to the stop motion surface. Thus when the door is opened the head of the stirrup (the other end of the stirrup being held in the bearing 21 in a manner enabling it to tilt) is drawn away in a manner which releases it from the tilted position brought about by the spring 29 and stops the braking effect of the brake drum 24; the latter thus moves freely with the axle I2. This continues as long as the door is being opened and the direction of rotation of the axle I2 remains unchanged. At the moment when the direction of rotation of the axle is reversed by the closing of the door, the stirrups 26 are tilted, because now, by means of friction, the reversed rotation of the brake drum 2!. presses the stirrups into just that direction in which they are also tilted by the elastic ring 28, i. e., the brake drum can now no longer turn in the casing I, but the axle I2 is still able to turn in the brake drum, together with the cone 2I that is attached to the'axle I2.

The purpose of the cone H is to enable the clos ing of the door to be adjusted to different speeds with the help of the adjusting device 6, I8, I9, 20 and the pressure spring II, since with the help of the adjustable spring pressure the friction arising between the surface of the cone and the brake drum 24 can be increased or diminished at will. If the braking effect is to be intensified, i. e., if the door is to be closed more slowly, this is done by screwing the cone 2I somewhat deeper into its seat by means of its adjusting device 6, I8, I9, I1, 20. If on the other hand the clos ng of the door is to be accelerated, the friction between the cone and the brake drum must be diminished and both parts given correspondingly more air between the friction surfaces by slackening the cone.

What I claim is:

1. In a door check, a casing, a tension cylinder having a bore therethrough and extending into-the casing from one end thereof, a spirally coiled spring surrounding said cylinder within the casing and having its ends secured to the cylinder and casing respectively, a shaft rotatably mounted in said bore and having an end projecting through the cylinder outside the casing, an operating lever mounted on said shaft end and operatively connected to said cylinder, the other end of said shaft projecting from the cylinder within the casing, a friction clutch member rotatably mounted on the last mentioned end of the shaft, a second friction clutch member splined on the. shaft and coacting with the first clutch member, means urging said clutch members into clutching relation, and means supported from the casing. within the latter to hold the first clutch member against rotation in one direction and to free the clutch member for rotation in the other direction.

2. In a door check, a casing, a tension cylinder having a bore therethrough and extending into thecasing from one end thereof, a spirally coiled, spring surrounding said cylinder within the casing and having its ends secured to the cylinder and easing respectively, a shaft rotatably mounted in said bore and having an end projecting through the cylinder outside the casing, an operating lever mounted on said shaft end and operatively connected to said cylinder, the other end of said shaft projecting from the cylinder within the casing, a friction clutch member rotatably mounted on the last mentioned end of the shaft, a second friction clutch member splined on the shaft and coacting with the first clutch member, means urging said clutch members into clutching relation, said first clutch member having a cylindrical exterior, gripping arms spaced circumferentially about said first clutch member, means supporting said arms from said casing, and spring means biasing said arms into gripping relation with the first clutch member.v

3. In a door-check, a casing, a tension cylin-' of the shaft, a second friction clutch member splined on the shaft and coacting with the first 1 clutch member, means urging said clutch members into clutching relation, said first clutch member having a cylindrical exterior, gripping arms extending longitudinally of the first clutch member and spaced therearound, said arms each having an inwardly extending finger projecting radially of one end of the first clutch member, fixed seats carried by the casing and having' said fingers loosely mounted therein, a supporting ring fixed to the casing at the opposite end of the ilrst clutch member and having peripheral slots fixed to rotate with the shaft and the'fem'ale' member being rotatable on the shaft, means car-- ried by the casing for limiting rotative movement of the female member and including springs normally holding :saidfemale member against rotation, said male' member be g adjustable to desired frictional relation with the female member, and means for eflecting adjustment of the male member.

5. In a spring biased door check, a stationary member, a second member associated therewith and rotatable relative thereto as the door is opened and closed, a clutch member including a driving and driven member carried by said rote-table member, means frictionally connecting said driving member and said driven member, at least one U-shaped stirrup tiltably carried by said stationary member, and means normally tilting said stirrup to a position to engage said driven member and prevent rotation thereof as said door is closed whereby to exert a braking influence on said driven member.

6. In a spring biased door check, a stationary member, a second member associated therewith and rotatable relative thereto as the door is opened and closed, a clutch member including a driving and driven member carried by said rotatable member, means frictionally connecting said driving member and said driving member, at' least *one U-shaped stirrup tiltably carried by said stationary member. and means normally tilting said stirrup to a position to engage said driven member and prevent rotation thereof as said door is closed whereby to exert abraking influence on sai'ddriven member, said position ofsaid U-shaped member permitting free rotation of said driven member with said driving member as the door is opened.

7. The structure of claim 5, said driven member and said driving member being'movable rel-- tension of said spring means;

8. The structure of claim 5, said driving mem--' ber comprising a frustro-conical member, said driven member comprising a complementary drum receiving the same, and said vU-shaped stirrup engaging the periphery of said drum the purpose set forth.

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